Security comes at a price, something which has become very obvious recently with the Meltdown and Spectre Speculative Execution vulnerability, which affects one of the ways processors speed up execution of applications, and who’s avoidance may now have long-lasting effects going forward.

Another security feature well known for slowing down PCs are antivirus software, but until now I had not realized how profound its impact was.

AV-Test.org regularly publishes the result of their suite of tests against popular antivirus software, and it was the above tab (for Windows Defender) which drew my interest.

According to their suite of tests, a typical antivirus app will slow down the loading of websites by 11-16%, slow down the launch of applications by 9-15%, slow down the installation of applications by 26-35% and the copying of files by 7-18%.

The above numbers are just averages and some applications are better and some worse. Windows Defender, for example, may slow down the installation of applications by as much as 54%.

AV-Test.org’s high-end PC is no slouch, with an Intel i7 3770 @ 3,40GHz, 16 GB RAM, Samsung 512 GB SSD, and it does make one wonder what the point of all that hardware is with such a pervasive halter slowing it down.

Of course, having an antivirus is very important, but if performance is important for you it may be a good idea to choose your antivirus well before upgrading to the latest processor and SSD for example.